The present invention relates to an improved apparatus for removing solid material or contaminants from an air stream. More particularly, this invention relates to an improved apparatus for removing or filtering solid contaminants from an air stream which is subjected to heat exchange to produce air useful for heating or cooling purposes.
Many residential housing units and other buildings are heated or cooled by the circulation of air through a heating furnace or cooling unit, where the air is warmed or cooled by heat exchange. The air is then passed to the room or rooms which it is desired to heat or cool. At least a portion of the air may be recycled between the plant and the area to be heated, or cooled several times, with make-up air being added as desired.
In order to insure efficient heating and cooling plant operation, one or more furnace filters are placed in the path of the air flow which is subjected to heat exchange in the plant to remove solid material or contaminants from the air. Without such filters, the heat exchange surfaces of the heating or cooling plant would tend to become coated with such solid material and become less effective.
One problem with conventional "throw-away" filters of the type described above is the frequent changing of the entire filter, including frame. Not only are such replacement filters expensive, but they also take up valuable storage space. Other filters can be washed and are thus reusable. However, such washing is a tedious and somewhat dirty job.
Therefore, one object of the present invention is to provide an improved apparatus for removing solid material from the furnace air flow.
Another object of this invention is to provide an improved apparatus for removing solid material from an air flow which is subjected to heat exchange and which apparatus is easily maintained for efficient removal of solid material. Other objects and advantages of the present invention will become apparent hereinafter.
An improved apparatus for removing solid material from air which is subjected to heat exchange to produce air useful for heating or cooling purposes has now been discovered. This apparatus comprises a filter frame means which defines a filter area preferably a substantially rectangular area, through which at least a portion of the air stream flows; and a supply means located in proximity to the frame means to supply filter medium to the filter area. The filter medium is constructed to remove at least a portion of the solid material, such as dust, lint and the like, entrained in the air flow as the air flows through the filter area. The filter frame means and the supply means co-operate so that the filter medium which is removed from the filter area is replaced by filter medium from the supply means. That is, for example, as the filter medium in the filter area becomes ineffective because of prolonged use and/or excessive contamination with solid material, it is removed from the filter area and replaced by fresh filter medium from the supply means. The simplified removal and replacement of filter medium in the present apparatus provides for improved filtration effectiveness, ease of operation, and maintenance, without the necessity of replacing the entire filter frame means every time the filter medium in the filter area is to be changed.
In one preferred embodiment, the present apparatus further comprises cutting means located at or near at least one end of the frame means to cut the filter medium being removed from the filter area from filter medium within the filter area. This embodiment is particularly applicable where the filter medium, such as paper, cloth, porous metal, foil, porous resineous foam and the like, in the filter area is attached to the filter medium in the supply means. The filter medium in the filter area is removed by uging this filter medium toward the end of the frame means equipped with the cutting means. As the filter medium is pulled from the filter area, it is replaced by fresh filter medium from the supply means. After the desired amount of filter medium is pulled from the filter area, the cutting means is employed to separate the removed filter medium from the medium in the filter area. This cycle can be repeated as often as necessary for efficient air stream filtration.
In another preferred embodiment, the present apparatus further comprises porous support means located in the filter area, preferably attached to the frame means, which acts to support the filter medium in the filter area. One particularly preferred construction of the porous support means involves two support members, each preferably attached to the frame means, situated in the filter area so that the filter medium in the filter area is positioned between the support members. This construction has been found to provide optimal support for the filter medium in the filter area without unduly interferring with the operational efficiency of the entire filter assembly.
The present supply means is preferably removably attached to the frame means at or near one of the ends of the frame. In one preferred embodiment in which a cutting means is employed, the supply means is attached to the frame means at or near the end of the frame means, substantially opposite the end of the frame means at or near which the cutting means is located. In this manner the supply means can supply filter medium to substantially the entire filter area and the removed filter medium can be effectively and efficiently detached from the filter medium in the filter area. In an additional embodiment, the present supply means is constructed so as to allow a quantity of fresh filter medium to be included therein after the supply of filter medium in the supply means is exhausted. For example, when the supply means is empty, a fresh supply of filter medium may be added so that filter medium may continue to be supplied to the filter area. Thus, prolonged periods of time and/or many changes of filter medium may occur without requiring the replacement of the filter frame or, for that matter, any other component of the present apparatus.
These and other aspects and advantages of the present invention are set forth in the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.